1. Field of the Invention
The present invention relates generally to an apparatus and method for use in the percutaneous insertion of medical devices. More specifically, the present invention relates to a gastro-intestinal tube placement device which includes a trocar, an access tube having an internal retention portion at its distal end for engaging an internal gastric wall, and an overtube.
2. Description of the Related Art
Medical practitioners utilize a variety of gastro-intestinal devices to access the gastro-intestinal tract. One type of gastro-intestinal device, the gastro-intestinal tube or gastrostomy tube, is widely used with patients who require catheterization for the purposes of, for example, delivering food or medication to the gastro-intestinal tract, draining the tract, or creating a surgical port.
Medical practitioners often use Percutaneous Endoscopic Gastrostomy (PEG) techniques, such as those described in U.S. Pat. Nos. 4,861,334; 4,900,306; and 5,080,650, to place tubes within the gastro-intestinal tract. These techniques typically involve a trans-oral approach of placing a gastro-intestinal tube in the patient's mouth and snaking it down the esophagus, into the stomach, and out the abdominal wall. Other techniques involve percutaneously inserting a tube into the stomach from outside of the abdominal wall by sliding the tube over a guidewire.
Practitioners have encountered numerous problems with the trans-oral techniques, which are complicated and cumbersome, often requiring more than one person to perform. Many of the problems are caused by dragging the gastro-intestinal tube through the anatomy. Problems such as patient discomfort, esophageal trauma, internal bleeding, and gastro-esophageal reflux condition are caused or exacerbated by dragging of the gastro-intestinal tube through the esophagus. In addition, the risk of abdominal infection is increased due to the dragging of the gastro-intestinal tube through non-sterile areas such as the mouth and esophagus prior to placing the tube in the gastric and abdominal walls.
Practitioners have also experienced problems with techniques involving the percutaneous insertion of a tube. Some such problems are due to the fact that there is often no retention of the stomach wall's position with respect to axis of insertion. The stomach wall is often pushed distally during insertion, causing it to drift away from the abdominal wall. As the gastric wall drifts, the site chosen for tube placement within the gastric wall is lost. The lack of retention of the gastric wall makes dilation of the abdominal and gastric walls difficult, and allows for unintentional and undesirable pneumoperitoneum.
Other problems experienced with percutaneous insertion techniques are caused by the sequential insertion of dilation devices that are often involved. The abdominal wall, which is not particularly suited to sequential dilation, is often traumatized during the process. In addition, the sequential passage of devices prolongs the time needed to perform placement, and potentially leads to undesirable pneumoperitoneum.
Therefore, it is desirable to provide an improved apparatus and method for the placement of gastro-intestinal tubes, and more generally, the placement of any internal medical device.